diff --git a/tools/python/jwutils/algo/ShuntingYard.py b/tools/python/jwutils/algo/ShuntingYard.py
index c641b09..dc20e6e 100644
--- a/tools/python/jwutils/algo/ShuntingYard.py
+++ b/tools/python/jwutils/algo/ShuntingYard.py
@@ -88,7 +88,7 @@ class ShuntingYard(object): # export
 
         scanner = re.Scanner([
           (regex,       lambda scanner,token:(KEYW,   token)),
-          (r"('|\")[^'\"]*('|\")",  lambda scanner,token:(QUOTED, token[1:-1])),
+          (r"\"[^\"]*\"|'[^']*'",  lambda scanner,token:(QUOTED, token[1:-1])),
           (r"[^\s()]+", lambda scanner,token:(ARG,    token)),
           (r"\s+",      None), # None == skip token.
         ])